密封熔炼炉HFC134a氮气中保温时间对AZ91D镁合金保护的影响  

Effects of Holding Time on AZ91D Magnesium Alloy Under N_2 Atmosphere Containing HFC134a in a Sealed Melting Furnace

作　　者：聂书红[1] 熊守美[1] 

机构地区：[1]清华-东洋镁铝合金成形技术研究开发中心清华大学机械工程系,北京100084

出　　处：《铸造》2006年第2期112-115,共4页Foundry

基　　金：清华-东洋镁铝合金成形技术研究开发中心研究项目;博士后基金资助项目(2004035319)

摘　　要：HFC134a适合充当镁合金在密封熔炼炉中的保护气体,氮气是一种好的稀释气体。与常规熔化炉相比,保护气体用量很少。不管有无表面搅拌,在保温时间分别为2h、5h或10h时,AZ91D镁合金均被很好保护,没有观察到蒸发物。所有表面膜形貌呈致密胞团状,表面膜厚度约为1.5μm,且比较均匀。随着保温时间增加,表面膜中C含量逐渐减少到零,氧含量逐渐升高。炉内气氛对熔炼炉内壁无可观察到的腐蚀。HFC134a is suitable for the protective gas of magnesium alloys and N2 is a good dilution gas for HFC134a. The consumption of the protective gas is less than that of the conventional melting furnace of magnesium alloys. The AZ91D alloy was protected well with or without stirring under a holding time of 2 hours, 5 hours or 10 hours, no evaporation was observed during the experiments. The surface morphology is a compacted cellular form with an evenly distributed thickness of about 1.5 μm. With the increase of the holding time, the C content in surface films decreases to zero, and the O content increases gradually. No corrosion of the atmosphere to the inner wall of the furnace was found durina the experiments.

关 键 词：AZ91D镁合金 表面膜 保温时间 HFC134A 密封 

分 类 号：TG27[金属学及工艺—铸造]